This disclosure relates to wireless networks and devices and more particularly to where some users, operating on a prepaid basis, are allowed to roam beyond their home network to other visited networks.
Growth in the use of personal wireless devices continues at a rapid pace. The wireless communication market now supports not just mobile handsets, but also mobile and fixed wireless broadband access devices, wireless local area network equipment, laptop computers, personal digital assistants, smart phones, tablet computers, wireless routers, wireless network attached storage devices and a seemingly endless array of applications.
Wireless networks have traditionally relied on a paid subscriber model where each individual user must pay for access to the network in some fashion. Historically this had been done on a month to month subscription basis, it is increasingly popular especially in developing markets for users to opt for a prepaid model. That way, users can control the amount which they spend and service providers can assure that they will receive revenue in advance for its use.
It is also desirable for users to be able to use their devices outside their home network, such as when they are travelling. There are existing solutions for providing this functionality. International Patent Publication No. WO00/024161 entitled “Charging Method in Telecommunications Network” describes one approach applicable for a GPRS (General Packet Radio Service) packet data service that are provided over a Global System for Mobile (GSM) network. In these networks a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN) are connected via an intra-operator backbone network. The SGSN may be a gateway device located where the subscriber is, that is, in the roaming network, and the GGSN located at a gateway in the subscriber's home network. The approach described here implements a Camel Service Environment (CSE) in all of the various SGSNs and GGSNs, so that a billing unit can then be responsible for debiting a prepaid account on the basis of information it receives from the CSE-enabled gateways.
In another approach described in European Patent Application EP 1223737 entitled “Providing Prepaid Services to a GPRS Mobile Station when Roaming”, it was recognized that the Camel Service Environment requires both the visited network and the home network to each support the same Camel level (for example, Camel Phase 3). In another approach described here, a prepaid service data maintaining node is operated under control of the home network service provider. The prepaid service data maintaining node provides the gateway nodes with information data and/or instructions concerning the prepaid data service operated by the home network, even when not all of the SGSN themselves participate in Camel.
International Patent Publication No. WO02/41592 entitled “Network Requested Packet Data Protocol Context Activation” describes a particular method for providing a Packet Data Protocol (PDP) context activation in a core network based on GSM to provide Third Generation Partnership Project (3GPP2) data services. The GGSN in this network maintains routing information for Packet Switched (PS) users. The routing information can be used to tunnel Protocol Data Unites to a Mobile Station's current point of attachment, i.e., the SGSN.